Magneto



B. BONOMINI AND L. DUCA.

MAGNETQ.

APPLICATION FILED Aue.2a. 1919.

1,37 2,739. P ted Mar. 29, 1921.

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Bruno Bonom/ni Zr [ll/571' Ouca.

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B. BONOMINI AND L. DUCA.

MAGNETO.

APPLICATION FILED AUG-28. 1919.

Patented Mar. 29, 1921.

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flfforney.

v, UNITED STATES,

PATENT OFFICE.

BRUNO BONOMINI AND LUIGI DUCA, OF TURIN, ITALY, ASSIGNORS T0 SOCIETA ANONIMA A. G. 1)., OF MILAN, ITALY, A CORPORATION OF ITALY.

MAGNETO.

Specification of Letters Patent.

Application filed August 28, 1919. Serial No. 320,412.

To all whom it may concern:

Be it known that we, BRUNO BONOMINI and LUIGI DUOA, subjects of the King of Italy, and residents of Turin, Italy, have invented certain new and useful Improvements in Magnetos, of which the following is a specification.

This invention relates to magnetos for ignition in combustion engines, and has for its object a magneto having a stationary armature which is provided with magnetic cores carrying the primary winding and with magnetic bridges, the magnetic. flux passing through said armature always in the same direction and being directed in an alternating succession through said cores and bridges to produce variations in the value of the magnetic field interlinked with the primary winding and therefore an induced current in said winding.-

The above described operation is obtained by means of plates or disks rotating in front of the ends of said armature, these disks being made of non-magnetic material and having embedded segments or portions of magnetic material.

The annexed drawings showby way of example a construction of the magneto according to this invention; Figure 1 is a vertical section of the magneto in the plane of the axis of the shaft; Fig. 2 is a transverse section on line m-w Fig. 1; Fig. 3 is a front view of one of the outer walls of the stationary armature; Fig. 4 is a front view of one of the rotating disks; Fig. 5 is the cesses for the passage of the shaft 5 this latter being arranged perpendicularly with regard to the arms of said magnets as shown by Fig. 1.- v

Shaft 5, which is intended to be operated by the engine, is mounted on ball bearings 6 seated in said box 1 and passes through a drum providedxat'its ends with hollow journals 7-7 seated in holes 4;. Said drum comprises two cups 8 made of non-magnetic material and integral with said journals 7 in which are inserted or embedded iron segments or pieces 9 (Figs. 1 and 3), and two additional cups 10, likewise made of non-magnetic material, these cups 10 being clamped between cups 8 and being arranged w th their mouths opposite and in contact with each other so as to provide an intermediate chamber or space therebetween. Between the transverse walls of cups '10 are arranged four magnetic cores 11, which proect through holes made in said walls and which terminate flush with the outer surfaces thereof to form segments 12. Four,

rods or bridges 13 of magnetic material are also arranged to extend through the walls of cups 10 and terminate flush with the outer surfaces thereof (see Figs. 1, 2 and 5).

A disk 14 is arranged in each free chamber left between associate pairs ofwalls or cups 8 and 10, said disks being made of nonmagnetic material and provided with iron segments 15 inserted or embedded therein (Fig. 4).

Cups 8 and- 10 therefore jointly constitute a closed drum adapted to be rotated around journals 7, the shaft 5 with the disks 14 rotating freely in'the drum.

On each core 11 is wound one section of the primary winding 16, this latter comprising a further section 16 wound on the frame or sup-port formed by the cores l1 and bridges 13. Around said primary winding is wound the secondary winding 1 located wlthin the chamber inclosed bycups 10, this winding having one of its ends connected with a contact segment 18 mounted on an insulating extension 18' of said drum. A brush 19 is held in contact with segment 18 by means of a spring 19 and said brush 19 and spring 19' are mounted in an insulating socket'28 provided on a shaft 29, fixed to a rotating member 21 of the current distributer which is operated under proper ratio 'by means of a.pinion 22 meshing with a pinion 23 fixed to shaft 5. l

Said member 21 is provided with a brush 20 which is carried around in rotation by it and is adapted to contact with plugs, not shown, leading to terminals of the distributer as usual. Brush 19 is connected electrically with brush '20. the secondary current induced in the winding 17 being thus fed rich as to insur'e'the closing of the magnetic through section 1-8 and brushes 19 and 20 to distributer terminals.

The drum formed by cups 8 and 10 is rigidly connected with a member 24 operated by a lever 25 so that by shifting this lever the drum may be displaced angularly .With regard to disks 14.

During the operation of the magneto, the drum consisting of cups 8--10 is stationary, while shaft 5 and its disks 14 are rotated. The magnetic flux produced by magnets 22 is collected by the magnetic segments 9 of the transverse walls of cups 8 and is led to the inner surfaces thereof so that it tends to pass through cores 11 and bridges 13. The conditions of the magnetic circuit are modified in a continuousmanner during rotation of shaft 5 and disks 14 located between cups 8 and 10 as when the magnetic segments 15 of disks 14 are in register with the segments 9 and 12 of cups 8 and 10, the magnetic flux passes through cores 11, and on the contrary'when the non-magnetic portions of disks 14 come opposite said segments 9 and 12 the flux does not pass through cores 11 but on the contrary is directed through bridges 13, the segments 15 of disks 14 being at this time in front of the ends of said bridges.

I of a condenser 30. V

The lines of force coming from a pole to the opposite magnet are thus directed through different paths according to the positions of disks 14 with regard to the magnetic segments of cups 8, but they are always closed through either cores 11 or. bridges 13; thus said lines are never broken andtherefore the magnets are permanently short cir-, cuited, so that they are not liable to become demagnetized. .1-

The magnetic flux through cores 11 is on the contrary broken at given periods; in the construction illustrated at each revolution of shaft '5 four maximum and four minimum values of flux are obtained in said cores and therefore a pulsating current is produced in primary winding 16-16.

This current is interrupted in the known 7 manner at proper times and gives rise in the secondary winding 17 to a high voltage induced current.

Said interrupting device is not shown in the drawing as it may be of any well known and suitable type and therefore does not form a feature of this invention. As usual the contacting parts of said interrupting device may beconnected with the arinatures Theangular' extension or width of the magnetic segments 9, 12 and 15 of cups 8 ;ing edgeof 631011 201 them is coming-out of and 10 and disks 14, respectively, must be {such an angular-width that when the trailregister with a segment 9 of cup 8 the leading edge of the same segment 15 is still in re ister with the next segment 9.

y this arrangement each segment 15 of disks 14 is at any time in register either with one of segments 12 of cup 10, and therefore with one of cores 11, or with one of bridges 13 or with both a segment and the adjacent bridge.

It is advisable that the primary winding be wound partly on individual cores 11 and partly on the frame formed of said cores and the bridges 13 so as to give rise to an outer section 16 as above described.

Sections 16 of said primary winding may be connected either in series or in parallel with sections 16 as shown in Figs. 6-7 and 8.

In the case of Fig. 6 the foursections 16 are in series and they are further connected in series with said section 16; in the case of Fig. 7 said sections are connected in parallel with one end of section 16', and finally in the construction of Fig. 8 each winding 16 is connected witha different point of said winding 16 these points being equidistantly spaced apart from each other.

Obviously the shape and number of cores 11, bridges 13 and segments 9, 12 and 15 may be difierent from those described and illustrated; by varying the number of said parts a different number of variations in the magnetic flux value may be obtained at each revolution of the'shaft. Further, by modifying the extension of the segments, cores, and bridges, sparks having different characters may, be obtained, the magnets being in any case permanently short-circuited. T 4

Magnetos according to this invention may be operated in either direction, it being sufiicient for thispu'rpose to modify the respective position of magnetic segments 9 of cups 8 and of segments 12 of cups 10. To this end cups 8 are provided with two holes 26 and 26' for each hole 27 provided in cups 10, connecting screws being inserted through holes 27 and either of holes 26 and 26' so that the magneto may be easily adjusted according to requirements.

Finally the time at which the ignition takes place may be adjusted by operating lever 25 and member 24, the displacement of said parts modifying the respective position of the drum 8-10 with respect to disks 14 the rotation of which is timed with the operation of the engine; the angle through which the ignition point is displaced may vary up to 90 without reduclng the character of sparks, as the induced current has a constant value notwithstanding the inducing magnetic field is displaced.

,. Magnets built in accordance wlth the described construction do not require a careful machining and require only a small amount g and associated parts.

of iron, thus reducing dispersion of the magnetic field.

What we claim as our invention and desire to secure by United States Letters Patent is l. A magneto for ignition in explosion engines comprising permanent magnets, a drum of non-magnetic material arranged between the arms of said magnets, the front walls .of said drum having magnetic portions to form a path for the magnetic flux of said magnets, two non-magnetic transverse partitions in said drum, magnetic cores and bridges extending from the outer face of one partition to-that of the other, said adjacent walls and partitions forming two chambers at the ends of the drum, a shaft extending through said drum and operated by the engine, non-magnetic members located in said chambers and fixed to said shaft, said members having magnetic portions embedded therein to direct thev magnetic flux through either said cores or bridges upon rotation thereof, a primary winding on said cores, means for interrupting the primary current induced therein, a secondary winding interlinked with said primary winding and located within said drum, and means for distributing the secondary current to terminals.

2. A magneto for ignition in explosion engines comprising permanent magnets, a drum of non-magnetic material arranged between the arms of said magnets, the front walls of said drum having magnetic portions to form a path for the magnetic flux of said magnets, said walls having hollow journals seated in said magnets, two nonmagnetic transverse partitions in said drum, magnetic cores and bridges extendin from the outer-face of one partition to 51 the other, said adjacent walls and partitions forming two chambers at the ends of the drum, a shaft extending through said journals and drum and operated by the engine, non-magnetic members located in said chambers and fixed to said shaft, said members having magnetic portions inserted therein to direct the magnetic flux through either said cores or bridges upon rotation thereof, a primary winding on said cores, means for interrupting-the primary current induced therein, a secondary winding interlinked with said rlmary winding and located within said rum, means for distributing secondary current to terminals, and' means for displacing angularly said drum 3. Av magneto for ignition in explosion engines comprising permanent magnets, a drum of non-magnetic material arranged I between the arms ofsaid magnets, the front walls of said drum having magnetic segf ments to form a path for the magnetic flux of saidmagnets, two non-magnetic transat of operated by the engine, non-magnetic members located in said chambers and'fixed to said shaft, said members having magnetic segments inserted therein to direct the mag- 'netic flux through either said cores or bridges upon rotation thereof, the angular extension of said segments being such that said magnetic flux is permanently direc d through either of said paths during he rotation of said members, a primary winding on said cores, means for interrupting the primary current induced therein, a secondary winding interlinked with said primary winding'and located within said drum, and means for distributing the secondary current toterminals.

4. A magneto for ignition in explosion engines comprising permanent magnets, a drum of non-magnetic material arranged between the arms of said magnets, the front walls of said drum having magnetic portions to form a path for the magnetic flux of said magnets, two non'magnetic transverse partitions in said drum, magnetic cores and bridges extending from the outer face of one partition to that of the other, said adjacent walls and partitions forming two chambers at the end of the drum, a shaft extending through said drum and operated by the engine, non-magnetic mem-- I bers located in said chambers and fixed tomagnetic flux through either said cores or bridges upon rotation thereof, means for connecting together in two different respective positions the said walls and partitions of said drum according to said direction of rotation of said shaft and members, a primary winding on said cores, means for interrupting the primary current induced therein, a secondary winding interlinked with said primary winding and located within said drum, and means for distributing the secondary current to terminals.

5. A magneto for ignition in explosion engines comprising permanent magnets, a drum of non-magnetic material arranged between the arms of said magnets, the front walls of said drum being provided with magnetic portions to form a path for the magnetic flux'of said magnets, two non-magnetic transverse partitions in said drum, magnetic cores and bridges extending from the outer face of one partition to that of the other, said adjacent walls and partitions forming two chambers at the ends of the drum, a shaft extending through said drum and operated by the engine, non-magnetic with sald primary winding and located with:

in said drum, and means for distributing the secondary current to terminals.-

6. A magneto for ignition.,,- in explosion engines comprising permanent magnets,

cores adapted 'to direct the magnetic flux thereof, bridges adapted to direct said flux, a shaft operated by the engine and having means moving between the poles of said magnets and said cores and bridges to direct the magnetic flux through either said cores or bridges in succession tovary the value of the magnetic field in said cores, a primary winding comprising coils wound on said cores and a section encircling said coils, said coils being connected by sets with one end of said section, means for interrupting the primary current induced therein, a secondary winding interlinked with said primary winding, and means for distributing the secondar current to terminals.

, 7. magneto for ignition in explosion engines comprising permanent magnets, cores adapted to direct the magnetic fiux thereof, bridges adapted to direct said flux, a shaft operated by the engine and having means moving between the poles of said magnets and said cores and bridges to direct the magnetic flux through either said cores or bridges in succession to vary the value of the magnetic field in ,said cores, a

8. A magneto for ignition in explosionengines comprising permanent magnets, a

drum of non-magnetic material arranged between the arms of said magnets, the front walls of said drum having magnetic portions to form a path for the magnetic flux of said magnets, two non-magnetic transverse partitions in said drum, magnetic cores and bridges extending from the outer face of one partition to that of the other, said adjacent walls and partitions forming two chambers at the ends of the drum, a shaft extending through said drum and operated by the engine, non-magnetic members located in said chambers and fixed to said shaft, said members having magnetic portions embed ded therein to direct the magnetic flux through either said cores or bridges upon 1 rotation thereof, a primary winding on said cores, means for lnterrupting the primary current induced therein, a secondary winding interlinked with said primary winding and located within said drum, and means for distributing the secondary current to terminals.

In testimony whereof we have signed our names to this specification in the presence of witnesses.

BRUNO BONOMINI.

LUIGI DUCA.

two subscribing Witnesses:

CARno CoR'ro, GIUSEPPE DE L110. 

